Fluid pumping



April 29, 1930. L. F. WHITNEY 1,756,802

FLUID PUMPING Filed Jan. 6, 1927 3 Sheets-Sheet l I-I-I-III-IH-I-HII-I April 29, 1930. WHITNEY 1,756,802

FLUID PUMPING Filed Jan 6, 1927 3 Sheets-Sheet 2 llllllllllIIIIIIIIIIIIIIII IILIJGJ7/I/ZIII" l/yyzzfl/llfi (ff/14y:- I

, mum pumping efiiciency may be attained Patented Apr. 29, 1930 W- STATES PATE' LYMAIN" F. WHITNEY, oE RoSTon, Ii/IASSAcHUSETTS, ASSIGNOR, BY MESNE' ASSIGN- MENTS, To sTAToR REFRIGERATION, Inc, A CORPORATION 0E DELAWARE FLUID PUMPING Application filed January 6, 1927. Serial No. 159,342.

This invention relates to means for pumping a fluid without the use. of moving mechanical parts, and more particularly to an improved method of inducing fluid movement by aspiration with a propellent fluid. While. pumping means of this-character is more particularly intended for use in a refrigeration system of the general type disclosed in the copending application of Eastman A. Weaver, Serial No. 733,699, filed August 23, 1924-, and my copending applications, Serial Nos. 159,343, 159,344, 159,345 and 159,346, filed on even .date herewith, this in vention is also applicable to a wide variety of useswherein pumping of a fluid byaspiration is desirable. Further aspects of the invention more particularly pertain to the use of improved pumping means of this character as applied to a refrigerating system of the type disclosed in the aforesaid copending applications, which system "in general comprises a refrigerant circuit'and a circuit for propelling fluid, which have a portion in common adjacent the outlet of the aspirator nozzle, whereby pumping of the refrigerant may take place.

Among the structural improvements involved in the present type of apparatus is an' improved arrangement of aspirators and propellent coolers or condensers, whereby ll'lfiXlfrom a given amount of propellant which has been heated to a given temperature. Accord ,ing to present conclusions based upon experiments and data upon refrigerating systems of this type, it appears that the greatest efficiency may be attained-from a system wherein the propellent fluidhas'a comparatively high density and high boiling point in comparison with. the' density and boiling point of the refrigerant under similar pressure conditions. For example, a propellent fluid having the characteristics of mercury has been found to be advantageous when used with a refrigerant such as water or water in a saline or caustic solution since the propellant may be readily separated from the refrigerant;-

and the system disclosed herein as illustrating. the preferred form of the invention is more particularly suited to fluids of this character.

Further objects and advantages of the invention will be apparent to those skilled in the art upon a reading of the subjoined description and claims in conjunction with the accompanying drawings, in which Fig. l is a schematic view of a refrigeration system involving the principles of this invention;

Fig. 2 is a detailed view tion and partly in section;

Fig. 3 is an end elevation of a portion of the apparatus; Y

Fig. 4 is a detailed sectional view of one liquid trap;

Fig. 5 is a plan paratus;

Fig. 6 is a sectional view of the p;

ig. 7 isa central longitudinal cross-section of one form of the aspirator for the second stage of compression; and

View of a portion of the appropellent partly in eleva- 1 semb y for the first stage of compression.

Referring to the accompanying drawings and more particularly to Fig. 1 thereof, the invention is illustrated as applied to a refrigerating system, which comprises a cooler 1, which may be situated in a household refrigerator or in any other region which it is desired to cool. Cooler 1 is connected by. a vapor duct 2 with a mixing chamber 3 into which aspirator nozzle 4 is adapted to emit the propellent fluid. The propellent fiuid receives its energy from a vaporizer 5 which may be heated by any suitable means, such as the gas burner 6 provided with primary air valve 101 and having a secondary air valve 102 venting into the outer tube 103 which surrounds the tube 104 for the primary mixture. The combustion chamber 107 with- 4 and 33 respectively. Asplrator nozzle 4 100 in the Vaporizer is provided With tlieoutlet .or exhaust funnel 9 for burned gases, smoke An upstanding outlet pipe 10' -45 "to trap 17,-the level of the'propellent liquid Y may preferably be of the conventional flared form to permit the release of the propellent fluid from the high pressure cham er 12 to the mixing chamber 3 and permit the pressure thereof to be transformed into kinetic energy, thus imparting a high velocity to the p:opellent fluid as it enters the mixing cham- Referring particularly to Fig. 8 it may be seen that a condenserfunnel 43 is in concentric alignment with the downwardly inclined nozzle 4, this duct in the-illustrated embodiment of the invention being comparatively elongate and having a comparatively small cross-sectional size, and being designed to receive a mixture of the propellant and propelled vapors and to impart ener to the refrigerant' fluid at the expense 0 the energy ofthe propellent fluid while concomitantly condensing the latter. If desired, a suitable drain 16 may be provided at the bottom of the mixing chamber 3 and extend downward to a liquid trap ,17, being adapted to receive condensed propel-lent fluid and to contain a static liquid column thereof to provide a liquid head to balance the boiler pressure, while preventing clogging of chamber .3 by condensed propellant. Funnel or duct" 43 may form a condenser for the propellent fluid, being surrounded by a suitable jacket'67 which may be connected with -'a cooling radiator 19 by the inlet andoutlet 21 and 22, respectively.

', Preferably the jacket, radiator, and connectmg pipes are partially filled with a volatile cooling agent, such as alcohol or water, which will at least have a depth sufiicient to seal the mount of inlet pipe 21. Heat conducted through the wall of duct 43 is. absorbed by the volatile cooling-fluid and causes the latter to evaporate and rise to the radiator 19 which may be provided with suitable cooling fins 24 to assist radiation of the heat. Funnel 43 is,

provided with a continuation 14 at the lowermost portion of which is located a suitable dram 35 for conducting condensed propellant in this pipe also forming a liquid column to balance boiler pressure.

.into the second stage mixing chamber cooling means of any desired form,

Preferably duct 43 has a downward in-; clinationas shown,.and pipe 14, forming a continuation thereof, has an-upward curve which is continued into a vertical portion 26,

which again is bent to provide an upwardly inclined portion 27, which, through the downward-extension 28, is adapted to emit'vapor lgreferably pipe 14 is provided with suitable such as plates 29.

vDue to the difference between the boiling points of the refrigerant and the propellent fluids, condensation of practially all of the propellant which passes through aspirator 4 occurs in duct 43 or in the mixing chamber 3, and therefore very little propellent fluid is carried upward through pipe sections 26 and I 27, further condensation taking place' in the latter pipes and resulting in drainage of the propellant back to duct 35. On the, other 4 chamber, and theref re the second stage nozj zle has a smaller volu e of refrlgerant vapor to pump.

As previously indicated, a second aspirator 33 is adapted to receive propellent vapor from one of the branches 11 of the pipe 10 and 1s adapted to impart the second stage of com pression to the refrigerant vapor. Pumping .of the fluid through compression tube 13 as a result of the second stage of aspiration takes place in a manner similar to that previously described, each of the aspirators and compression ducts preferably being shaped and proportioned to give the best pumpingefli- V c'iency in accordancewith vapor conditions in the respective stages. In a manner similar to that previously described in regard to the first aspirator assembly, compression duct 13 maybe provided with drains 16 and 35 as well as a cooling jacket 67 which has connections with'a second radiator 19.

The downwardly inclined compresslon 'fu'nnel 13 has an upwardly extending con-- tinuation 47, as disclosed in Fig. 3, which is adapted to emit the compressed vapor into aseparating chamber 46 from whence the vapor passes through pipe 50 to a condenser 49.

This condenser may be of any desirable form,

but may conveniently comprise, as shown, a

single pipe 50 having oppositely disposed open loops, the legs of which areinclined, whereby the condensed refrigerant will tend to flow down; the same to separating chamber 46. As shown, pipe 50 is provided with radiating fins 51, but any conventional, form of heat-absorbing means may be substituted for the same. The mixing chamber 46 has an outlet 71 which terminates in a .liquid trap 52, Fig. 6, having a connection- 53 with the cooler 1. Preferably the liquid trap 52. may comprise an upwardly inclined chamber'54 with I the end of pipe 71,pr0jecting downwardly into the lower part thereof, and this liquid.

trap may contain any liquid, such as the propellant, e. g., mercury, and is adapted to balance differences in pressure in the condenser 49 and the cooler 1. When a suitable amount of condensed fluid has gathered in-tube 71, the liquid in the other .leg of the trap will be forced upwardly and outwardly sufficient to admit the passage of'some of the liquid refrigerant in tube 71 about the lower end of that tube, whereupon, due to its lighter weight, it will rise to the top of the liquid in theopposite tube, and thus pass into the' cooler 1. Since a certain amount of residual -propellent fluid may be carried by the refrigerant past the separatingchamber 46 into the cooler 1, suitable means are provided to permit the drainage of the heavier liquid propellant back to the boiler 5, such means comprising a pipe 60 connected with the pipe 35 and adapted to hold a suit-able static liquid column in a similar manner. Pipe 60 comprises a liquid trap 61, which has a connection 63 with the cooler 1. Liquid trap 61 may preferably be sealed by propellent fluid, such as mercury, and upon the filling of its upstanding connection 63 with additional mercury, it will force the overflow of some of the mercury through the trap into the tube 60. It is advantageous to provide the liquid trap 61 Withtwo connections with the cooler (Fig.

'fl),'the outmost 64 of these connections pro- Jecting upwardly into thecooler to permit the I 1 upward flow-ofrefrigerant that may have been carried into the trap by the heavier propellant.

Pipe may'preferably project slightly into the intermediate part of an upwardly inclined leg of trap 17 (Fig. 2).. This leg terminates in pipe 16 and is adapted to permit the upward movement of any of the refrigerant which may have been entrained in the heavier mercury.

In the operation of a system of this character it is to be understood that liquid refrigerant in the cooler 1 is evaporated due to the action of the first stage aspirator, which causes somecompressionof thevapor in the funnel 13, the propellent fluid being condensed out of the refrigerant vapor and the latter being cooled in pipe 14: as it passes to the second stage mixing chamber when, by the action of the second aspirator, it is fur siderably compressed.

A salient feature of the invention consists I in that propellent vapor is condensed out against eflicient operation.

from the mixture of propellent and propelled fluids as soon as it has given up the effective portion of its kinetic energy so that the spent molecules of propellant do not -mitigate tion should be effected closely following the outlet of the aspirator and preferably along the portion of the passageway where the k1ne This condensa 4 tic energy of the propellant is being transferred to the other fluid. Thus in the illustrated embodiment this condensation takes place in the condenser funnels 4:3 and .13 1m 1 inediately follow ng the chambers 3, principally in the necks of the funnels preceding the flaring portion thereof.

The condensation of propellant in this same region also has the unique function of increasing the rate of diffusion of the propellent particles radially outwardly through the fluid to be propelled thus increasing the efliciency of aspiratiompy obtaining more inj v timate mixing of concentrated along the axis of the passageway and therefore with increased transference of kinetic energy from the propellant to the pumped fluid.

these particles of propellant which diffuse outwardly to the periphery, having thereby given up most of their eifective kinetic energy,

condensing'out so as not to impede the diffusion of succeeding particles.

lVhile I. have stage aspiration in conjunction with a refrigerating system, it is evident that the same principles affording similar increasedefliciency of pumping may adv-antageouslybe used in'other types of apparatus wherein aspiration of a propellent fluid is used to pump a second fluid; and in so far as the termspf the appended claims permit, I.- desire to 1n-.

two fluids with less tendency for the propellent stream to remain This action due to the removal by condensation ofthe propellant around the periphery of the passageway,

disclosed the use .of multiclude the use of this invention in all appro- I priate installations rather than confining the same to a refrigerating system of the type disclosed.

I claim: 1. The method of pumping fluidthrough a duct which comprises propelling thefluid at successive stages along the duct by-as iration with the vapor of a propellent hquid having a higher boiling point than the fluid, 3.

and after each of said stages removing the ropellent liquid as its energy is exhausted,

etween said stages further cooling the pumped fluid to a temperature above its condensation point, and condensing the fluid after the last stage of aspiration.

2. Apparatus of the character described comprising a fluid duct including. means for pumping fluid, said means com rising two 1 aspirator nozzles with propellen' condensers 15 adjoining the outlets of each of the same, a-

cooler between 'one' of the condensers and the succeeding aspirator, and a third condenser connected to the outlet of the condenser adjoining the outlet of the second aspirator nozzle. I

3. Apparatus of the character described comprisin a fluidduct including means for pumpin uid, said means comprising a plurality 0% aspirator' nozzles with propellent tor, each of the condensers adjoining the 5 aspirator nozzles having a restrlcted size and cooling area to efl'ect thecondensation of a propellentfluid having a high condensation temperature without condensing a pumped fluid having a lower condensation temperature.

QC.- Apparatus o'fthe character described comprising a fluid duct including means for pumping the fluid, said means comprising two aspirator nozzles with propellent condensers-adjoining the outlets of each of the same, a condenser connected to the outlet of the condenser adjoining the second aspirator, each of said condensers adjoining said aspirators having a restricted cross-sectional o passage in'concentric alignment with the I nozzles for efl'ecting the simultaneous .condensation of propellent fluid and compression of pumped fluid. a Y 5. Apparatus of the character described comprising a fluid duct including means for pumping the fluid, said means comprising two aspirator nozzles with propellent condensers adjoining theoutletsof each of the same, a cooler'betweenv one of the condensers and the succeeding as irator and a third condenser connected tot e outlet of .the condenser adjoining the second aspirator, each of said conportion of said duct being at least approxi- -mately twice as great as the distance between the nozzle outlet and the duct inlet.

8. Apparatus of theclass described coma diameter near that of the outlet of the nozzle, and said duct having an outwardly flared portion beyond the portion of smallest diameter.

Signed by me at Boston, Massachusetts,

this 20th day of December, 1926.

' LYMAN F. WHITNEY. l

densers adjoining said aspirator nozzle'hav-- ing a restricted size and cooling area to e'flectcondensation of a propellent fluid having a high condensation temperature without condensing a pumped fluid having a lower condensation pressure, said third condenser having a comparatively large heat distributing' area to effect condensation of pumped fluid at a-low temperature.

6. The art of pumping a condensable vapor with a condensable vapor having a higher condensation point which comprises impelling the first vaporby directaction thereon by the second vapor at successive locations, A condensing out; substantially all the second vapor entering thecycle at the first location intermediate the two locations, condensing tion following the second location, and at a subsequent location condensing the first out substantially all the second vapor entering the cycle at the second location at a locaprising means for ent'raining a pumped fluid in a stream of propellent vapor, including a mixing chamber having a fluid inlet, a propellent nozzle discharging into the mixing chamber at one side, a duct leading from the other side of the mixing chamber in a'lignment with said nozzle and having a portion of comparatively small cross-sectional area, and means to condense spent propellent vapor in said duct, the length of the small 

